import React, { FC, useState, createContext, CSSProperties } from 'react';
import classNames from 'classnames';
import { MenuItemProps } from './menuItem';

type MenuMode = 'horizontal' | 'vertical';
export interface MenuProps {
  // 默认 active 的菜单项的索引值
  defaultIndex?: string;
  className?: string;
  // 菜单类型 横向或者纵向
  mode?: MenuMode;
  style?: CSSProperties;
  // 点击菜单项触发的回掉函数
  onSelect?: (selectedIndex: string) => void;
  // 设置子菜单的默认打开 只在纵向模式下生效
  defaultOpenSubMenus?: string[];
}
interface IMenuContext {
  index: string;
  onSelect?: (selectedIndex: string) => void;
  mode?: MenuMode;
  defaultOpenSubMenus?: string[];
}

export const MenuContext = createContext<IMenuContext>({index: '0'});

export const Menu: FC<MenuProps> = (props) => {
  const { className, mode, style, children, defaultIndex, onSelect, defaultOpenSubMenus } = props;
  const [currentActive, setActive] = useState(defaultIndex);
  const classes = classNames('viking-menu', className, {
    'menu-vertical': mode === 'vertical',
    'menu-horizontal': mode !== 'vertical',
  });
  const handleClick = (index: string) => {
    setActive(index);
    if (onSelect) {
      onSelect(index);
    }
  }
  const passedContext: IMenuContext = {
    index: currentActive ? currentActive : '0',
    onSelect: handleClick,
    mode,
    defaultOpenSubMenus,
  }
  const renderChildren = () => {
    return React.Children.map(children, (child, index) => {
      const childElement = child as React.FunctionComponentElement<MenuItemProps>;
      const { displayName } = childElement.type;
      if (displayName === 'MenuItem' || displayName === 'SubMenu') {
        return React.cloneElement(childElement, {
          index: index.toString()
        })
      } else {
        console.warn('Warning: Menu has a child which is not a MenuItem component');
      }
    })
  }

  return (
    <ul className={classes} style={style} data-testid='test-menu'>
      <MenuContext.Provider value={passedContext}>
        {renderChildren()}
      </MenuContext.Provider>
    </ul>
  )
}

Menu.defaultProps = {
  defaultIndex: '0',
  mode: 'horizontal',
  defaultOpenSubMenus: [],
}

export default Menu;
